1 Scope
This document provides an appropriate reference spectral irradiance distribution to
be used in determining relative performance of solar thermal, photovoltaic, and other
systems, components and materials where the direct or hemispherical irradiance component
is desired.
This document provides one reference hemispherical irradiance spectrum, one reference
direct normal irradiance spectrum and 171 subordinate hemispherical tilted irradiance
spectra. The reference spectral irradiance presented in this document defines an air mass 1,5 solar spectral irradiance, for use in solar applications where a reference spectral
irradiance is required, for the direct normal radiation 5,8° field-of-view angle and
hemispherical radiation on an equator-facing, 37° tilted plane for albedo corresponding
to a light sandy soil. The reference spectral irradiance are intended to represent
ideal clear sky conditions.
The reference spectra and the subordinate spectral irradiances representing different
sky conditions are provided in .xls files available at https://standards.iso.org/iso/9845/-1/ed-2/en/